Improvement in hot-air furnaces



2 Sheets--Sheet1.

H. N. Luuarsuow.

Hot Air Furnaces.

Patented Jan. 28, 1873.

' WITNESSES 2 She'ts--Sheet2.

@ H. N. LONG FELLOW.

Hot Air Furnaces. o. 135,227. Patented Jan. 28,1813. v

AM PIIDTOLITHUGRAPHTL ca MX (osamns mam-s) UNITED STATES PATET OFFICE.-

HORATIO N. LONGFELLOW, OF LAWRENCE, MASSACHUSETTS.

IMPROVEMENT IN HGT-AIR FURNACES.

Specification forming part of Letters Patent No. 135,227, dated January28, 1873.

To all whom it may concern:

Be it known that I, Honarro N. LONGFEL- LOW, of Lawrence, in the countyof Essex and State of Massachusetts, have invented an Improvement inHot-Air Furnaces, of which the following is a specification:

The object of this invention is to effect a perfect down-draft in ahot-air furnace, which will heat all the hot-air pipes equally, andwhich cannot be affected by clogging. The nature of my invention isfully described below.

In the accompanying drawing, the bottom section of a radiator inside afurnace is shown, with some of its adjacent parts, and the base or bedof the furnace upon which the radiator rests.

Figure l is an elevation of that part'of the furnace embodying myinvention. Fig. 2 is a vertical section of the same. Fig. 3 is a plan ofthe upper side. Fig. 4 is a plan of the under side when taken 01f fromthe base. Fig. 5 is a top .view or plan of a portion of the base. Fig. 6is a front view of the lower end of adetached hot-air pipe, showing thegas-tight joint. Fig. 7 is a view of the same attached to the stave ofthe radiator, and connected with another section or piece of the hot-airpipe. Fig. 8 is a plan of the under side when removed from the base,showing particularly the sliding plates for use in cleaning the furnace.Fig. 9 is a sectional view of the same and for the same purpose.

Similar letters of reference indicate corrcsponding parts.

A is the base of the furnace. A is the center or bed-plate of the base Aof the furnace. B B are the openings in the base A. These openings B aremade at intervals around the base A, excepting under the down-draftopening, and supply air to the hot-air pipes. 0 c are broken linesrepresenting the position of the outside plate of the furnace. D D D arethe'staves forming the bottom section of the radiator. D and D arevertical. D is set at an angle. These staves are, of course, cast indifferent sections or segments. E is the grate and bottom of thefire-pot. F is the bottom of the ash-chamber, which is made to beremovable. By removing the bottom' F, which is simply a cover, accessmay be had to the base or bed plate A. This is desirable when cleaningthe furnace. G is the opening or draft beneath the fire to supply 'airto the same, as usual. H H are openings through the stave D. Theseopenings are placed at intervals around the stave to the draft G, andcommunicate with the hot-air pipes. K K are the hot-air pipes, (or thelower ends of them,) which are heated by radiation and carry the hot airto the diflcrent rooms in the house after having passed out of thefurnace. These pipes are (except in Figs. 6 and 7) represented as castin with the staves. 7

Figs. 6 and 7 represent the hot-air pipes K as detached from the stavesand arranged to be bolted thereto. K represents a shoulder, which isplaced in each pipe H, usually as a connection at the joints. (Secbroken lines, Fig. 2.) K represents the pipe to which it is joined. Thisjoint K is tight and secure from gas. L is the down-draft leading to thepipe, which passes to the chimney. L is the upper plate of thedown-draft L. M is the pipe leading from the down-draft L to thechimney. The upper draft (used when build ing the fire) leads also intothe pipe M before it reaches the chimney. N is a partition or plateintended to prevent the hot air from passing out of the down-draft Luntil it has come in contact with all the hot-air pipes.

It will be seen that there is no provision for closing the down-draft L.l? is a slide forming a part of the top L of the down-draft L. I

In Fig. 8 it is open, and closed in Fig. 9. It is made to slide, so asto easily clean out the furnace when necessary. It affords easy accessto the down-draft. R is a slide forming a part of one of the sides ofthe downdraft L. It passes from the down-draft L to the plate orpartition N. It is made to slide in order to clean out the furnaceeasily when desirable.

In practical operation my invention works as follows: WVhen building thefire the draft above the tire, or, in other words, the direct draft, isopen. When the fire is well going the direct draft is closed and theflames and heat are drawn down around the pipes K K, enveloping them,and, having passed around the plate N, pass out at the down-draft L. Ofcourse there is nothing new in simply having a down-draft, and the greatdifficulty with furnaces in which both the radiator D and pipes K arevertical and parallel is that after a year or so the down-draft becomesclogged and filled up, or the entrance to it does, and the furnace mustbe taken to pieces and rea paired and cleaned. This ashes and soot fillsaround the lower ends of the hot-air pipes, and prevents the heat fromgetting at them by radiation or otherwise. This is obviated in myinvention in two ways-first, the pipes do not pass down to the bed ofthe furnace,

but pass out at or rather enter at the stave D, so that there is no Wayby which the pipes H may possibly get surrounded by soot and the heathas continual access to them; second, there are good arrangements forcleaning the furnace. The cover F may be removed, and the slides P Rpushed out of place, (after removing, if necessary, the pipe M,) andeasy access is had to all portions of the furnace bespecified.

HORATIO N. LONGFELLOW.

Viitnesses:

HENRY W. WILLIAMS, E. H. OBER.

